1. Field of the Invention
The present invention relates to a developing container configured to contain developer, a method of manufacturing the developing container, a developing device using the developing container, and an image forming apparatus.
2. Description of the Related Art
Image forming apparatus are typified by, for example, a copying machine, a printer (a laser beam printer and an LED printer), a facsimile machine, a multifunction peripheral combining those apparatus, and a word processor, which are configured to form an image on a recording medium through use of various image forming processes.
The various image forming processes are typified by, for example, an electrophotographic image forming process using an electrophotographic photosensitive member as an image bearing member on which a latent image is to be formed, an electrostatographic image forming process using an electrostatographic dielectric member as the image bearing member, and a magnetographic image forming process using a magnetographic magnetic member as the image bearing member. The image bearing member on which a latent image is to be formed includes a rotary member such as a drum and an endless belt, and a sheet member such as a photosensitive sheet and an electrostatographic sheet.
A developing device refers to a device configured to develop a latent image formed on the image bearing member with developer, and includes at least a developing container configured to contain the developer, and a developing member configured to develop a latent image by applying, to the image bearing member, the developer contained in the developing container.
A process cartridge refers to a cartridge detachably mountable to an apparatus main body of an image forming apparatus configured to form an image on a recording medium, and includes at least an image bearing member, and a developing device configured to develop a latent image formed on the image bearing member with developer. The developing device includes at least a developing container configured to contain developer, and a developing member configured to develop a latent image by applying, to the image bearing member, the developer contained in the developing container. The apparatus main body refers to a part of the image forming apparatus excluding the developing device or the process cartridge.
The recording medium refers to a recording material on which an image can be formed, and is typified by, for example, a recording sheet, a resin sheet, a cloth, an envelope, and a postcard. The recording medium also includes an intermediate transfer belt, an intermediate transfer drum, and a display of an image display apparatus.
In the following description, the developer is referred to as “toner.” Further, the developing member configured to develop a latent image with developer by applying the developer to the image bearing member is referred to as “a developing roller.”
The developing device, the developing cartridge, and the process cartridge as described above are provided with an elastic sheet member (toner seal member) which abuts against the rotating developing roller over the length in its axial direction (roller longitudinal direction) to prevent leakage of toner through a space between the developing container and the developing roller. Further, the developing container is provided with a developing blade configured to regulate the thickness of a toner layer.
In the above-mentioned structure, the developing container, the developing roller, or a toner supply roller configured to supply toner to the developing roller may be deformed due to a change in atmospheric pressure and an impact during distribution, and hence the volume inside the developing container may be reduced. In this case, the atmospheric pressure inside the developing container becomes higher than the atmospheric pressure outside the developing container, and hence toner may leak through a space between the developing roller and the elastic sheet member or between the developing roller and the developing blade. This is because air blows out of the developing container due to the difference between the atmospheric pressure inside the developing container and the atmospheric pressure outside the developing container, which causes toner leakage concomitantly.
Therefore, in the developing device, the developing cartridge, and the process cartridge disclosed in U.S. Patent Application Publication No. US 2011/0103827 and Japanese Patent Application Laid-Open No. 2003-270939, a communicating hole through which the inside and outside of the developing container are communicated with each other is provided. Further, a filter member which allows passage of air and blocks passage of toner is provided so as to close the communicating hole. With this structure, the change in pressure inside the developing container is reduced.
However, when the developing container is formed of a plurality of frames such as a container and a cover, the communicating hole through which the inside and outside of the developing container are communicated with each other is provided in the container or the cover. After the filter member is bonded so as to close the communicating hole, the container and the cover are welded together by vibration welding, to thereby form the developing container. In this case, due to the vibrations generated in the vibration welding, the filter member bonded to the communicating hole vibrates like a drumbeat, and vibrational energy of the filter member is converted into thermal energy due to the friction and deformation occurring inside the filter member. The thermal energy raises the temperature of the filter member. As a result, the filter member may be melted.